urticaria
Hives, also known as urticaria, is a kind of skin rash with red or flesh-colored, raised, itchy bumps. Hives may burn or sting. The patches of rash may appear on different body parts, with variable duration from minutes to days, and typically ...
(hives) that are induced by an exogenous physical stimulus rather than occurring spontaneously. There are seven subcategories that are recognized as independent diseases. Physical urticaria is known to be painful, itchy and physically unappealing; it can recur for months to years.
Signs and symptoms
Urticaria are characterized by dermal
edema
Edema (American English), also spelled oedema (British English), and also known as fluid retention, swelling, dropsy and hydropsy, is the build-up of fluid in the body's tissue (biology), tissue. Most commonly, the legs or arms are affected. S ...
(wheal, swollen) and
erythema
Erythema (, ) is redness of the skin or mucous membranes, caused by hyperemia (increased blood flow) in superficial capillaries. It occurs with any skin injury, infection, or inflammation. Examples of erythema not associated with pathology inc ...
(flare, red), also known as hives. Hive lesions typically last less than 24 hours and are usually
itch
An itch (also known as pruritus) is a sensation that causes a strong desire or reflex to scratch. Itches have resisted many attempts to be classified as any one type of sensory experience. Itches have many similarities to pain, and while both ...
y (pruritic). Hives can appear anywhere on the body and they may change shape, move around, disappear and reappear over short periods of time.
Types of hives
Acute urticaria (short-term): can develop suddenly and will last less than six weeks. About one in six people will have acute hives at one point in their life.
Chronic urticaria (long-term): can develop suddenly and will persist more than six weeks. This type of urticaria is uncommon and occurs in only 0.1% of the population. 20% of people with chronic urticaria report still having problems 10 years after its onset.
Causes
The cause of physical urticaria is unknown but it has been suggested to be an
autoimmune
In immunology, autoimmunity is the system of immune responses of an organism against its own healthy cells, tissues and other normal body constituents. Any disease resulting from this type of immune response is termed an " autoimmune disease" ...
disease, suggesting that antibodies, which are produced by the immune system to protect humans from foreign microbes, are binding to body tissue and damaging it.
In some cases physical urticaria can be a symptom of an underlying health issue such as:
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Thyroid disease
Thyroid disease is a medical condition that affects the structure and/or function of the thyroid gland. The thyroid gland is located at the front of the neck and produces thyroid hormones that travel through the blood to help regulate many other ...
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Hepatitis
Hepatitis is inflammation of the liver parenchyma, liver tissue. Some people or animals with hepatitis have no symptoms, whereas others develop yellow discoloration of the skin and whites of the eyes (jaundice), Anorexia (symptom), poor appetite ...
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Infection
An infection is the invasion of tissue (biology), tissues by pathogens, their multiplication, and the reaction of host (biology), host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmis ...
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Cancer
Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Po ...
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Food allergies
A food allergy is an abnormal immune response to food. The symptoms of the allergic reaction may range from mild to severe. They may include itchiness, swelling of the tongue, vomiting, diarrhea, hives, trouble breathing, or low blood pressu ...
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Atopy
Atopy is the tendency to produce an exaggerated immunoglobulin E (IgE) immune response to otherwise harmless substances in the environment. Allergic diseases are clinical manifestations of such inappropriate, atopic responses.
Atopy may have ...
cholinergic urticaria
Cholinergic urticaria (CholU, CU) is a form of hives (urticaria) that is triggered by an elevation in body temperature, breaking a sweat, or exposure to heat. It is also sometimes called exercise-induced urticaria or heat hives. The condition is ...
solar urticaria
Solar urticaria (SU) is a rare condition in which exposure to ultraviolet or UV radiation, or sometimes even visible light, induces a case of urticaria or hives that can appear in both covered and uncovered areas of the skin. It is classified as a ...
chronic idiopathic urticaria
Chronic spontaneous urticaria (CSU) also known as Chronic idiopathic urticaria (CIU) is defined by the presence of wheals, angioedema, or both for more than six weeks. The most common symptoms of chronic spontaneous urticaria are angioedema and hi ...
Antihistamine
Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provides ...
agents are the typically prescribed drug for the treatment of physical urticaria. They block the effect of histamine, a compound produced by the body which forms a part of the local immune response consequently causing inflammation. Some research has suggested that the use of antihistamines and
antagonists
An antagonist is a character in a story who is presented as the main enemy or rival of the protagonist and is often depicted as a villain.
The cascade of events that link the autoantibody-antigen reaction with the production and release of histamine is not well characterized. Therefore, the focus of treatment for physical urticaria has been on characterizing the effectiveness of antihistamines rather than analysis of receptor binding or the pathomechanisms.
List of cutaneous conditions
Many skin conditions affect the human integumentary system—the organ system covering the entire surface of the Human body, body and composed of Human skin, skin, hair, Nail (anatomy), nails, and related muscle and glands. The major function o ...